Defining Groups of Elements and Attributes in XML Schemas

 <xsd:group name="purchaseType"> 
     <xsd:choice> 
         <xsd:element name="retail"/> 
         <xsd:element name="internet"/> 
         <xsd:element name="mailOrder"/> 
     </xsd:choice> 
 </xsd:group> 

 <xsd:attributeGroup name="deliveryDetail"> 
     <xsd:attribute name="method"/> 
     <xsd:attribute name="vendor"/> 
     <xsd:attribute name="dateShipped"/> 
     <xsd:attribute name="dateArrived"/> 
 </xsd:attributeGroup>